Problem: Express this product in scientific notation: $(6.90\times 10^{1})\times (8.00\times 10^{2})$
Start by collecting like terms together. $= (6.90\times 8.00) \times (10^{1}\times 10^{2})$ When multiplying exponents with the same base, add the powers together. $= 55.2 \times 10^{1\,+\,2}$ $= 55.2 \times 10^{3}$ To write the answer correctly in scientific notation, the first number needs to be between $1$ and $10$ . In this case, we need to move the decimal one position to the left without changing the value of our answer. $ $ We can use the fact that $55.2$ is the same as $5.520 \times 10$ $ = {5.520 \times 10} \times 10^{3} $ $= 5.520\times 10^{4}$